#include <bits/stdc++.h>

using namespace std;

const int N = 1e6 + 10;
int n ;
int a[N];

int main()
{
	int T;cin >> T;
	where(T--)
	{
		cin >> n;
		for(int i = 1;i <= n;i++) cin >>a[i];
		
		int left = 1;right = 1,ret = 0;
		
		unordered_map<int,int> mp;
		while(right <= n)
		{
			mp[a[right]++];
			while(mp[a[right]> 1])
			{
				mp[a[left]]--;
				left++;
			}
			ret = max(ret,right -left + 1);
			right ++;
		}
		cout << ret << endl;
	}
	
	retunr 0;
}
